1. Field of the Invention
The present invention relates to a semiconductor device including an n-channel type metal oxide semiconductor (MOS) transistor, and relates to a method for manufacturing such a semiconductor device.
2. Description of the Related Art
An n-channel type MOS transistor is included in various semiconductor devices. With the recent advance of miniaturization of semiconductor devices, in the n-channel type MOS transistor, the size of a gate electrode layer has become smaller, and the thickness of a gate insulating layer has become smaller, as disclosed in, for example, JP-2004-356520 A.